‘Light-Fingerprints’ Help Astronomers ID Exoplanets

Next time, on CSI: Outer Space—astronomers use “light-fingerprints” to uncover the mysteries of exoplanets. Researchers at Cornell University catalogued 19 of the Solar System’s most diverse bodies, in hopes of finding the next Earth-like world. The inventory, compiled by Lisa Kaltenegger and Jack Madden of the university’s Carl Sagan Institute, features known spectra and albedos (the ratio of reflected light) of various planets, moons, and dwarf planets. “We use our Solar System and all we know about its incredible diversity of fascinating worlds as our Rosetta Stone,” Kaltenegger, an associate professor of astronomy and director of the Institute, said in a statement. “With this catalog of ‘light-fingerprints,’ we will be able to compare new observations of exoplanets to objects in our own Solar System,” she continued, citing the gaseous globes of Jupiter and Saturn, the icy nature of Europa, the volcanic terrain of Io, “and our own life-filled planet.” Freely available on the Carl Sagan Institute website, the index includes high- and low-resolution versions of the data, and offers examples of how the colors of 19 Solar System models would change if they were orbiting stars other than our Sun. The full study, “A Catalog of Spectra, Albedos and Colors of Solar System Bodies for Exoplanet Comparison,” was published online in the journal Astrobiology, and is set to be featured on the print edition’s December cover. “Planetary science broke new ground in the ’70s and ’80s with spectral measurements for Solar System bodies. Exoplanet science will see similar renaissance in… [Read full story]